Ophthalmic instrument support and lighting system

ABSTRACT

The present invention provides a uniquely position adjustable ophthalmic instrument support table for use in conjunction with an examining chair and a lighting system which allows the user to program the desired room lighting independently for each of several inputs such as instrument switches, examination lights or other electrical devices used during an ophthalmic examination. The ophthalmic instrument support table includes a base unit and a table top mounted to the base unit by support structure allowing four degrees of freedom to adjust the location of the table top with respect to both the patient seated in the chair and the doctor examining the patient on the opposite side of the table. The lighting control system allows one or two circuits of room lights to be adjusted in intensity and to have this adjustment automatically recalled to set the programmed room lighting condition upon activation of the input.

This is a division of application Ser. No. 08/549,634, filed Oct. 27,1995.

BACKGROUND OF THE INVENTION

The present invention generally relates to ophthalmic stands andlighting systems designed to work in conjunction with such ophthalmicstands. The invention is more particularly directed to a uniqueadjustable instrument delivery table and a programmable room lightingsystem which operates in conjunction with various ophthalmicinstruments.

In the practice of ophthalmology, it has been common for both the doctorand patient to be seated and to provide the doctor with an instrumentdelivery table which may hold two different ophthalmic instruments. Thetable may be shifted between two positions to present one or the otherof the instruments directly in front of the patient. Various priorsystems have been proposed and utilized and some of these systems allowthe instrument delivery table to be rotated into position in front ofthe patient while others allow the table to be moved laterally from astored position into an operative position in front of the patient. Anexample of an ophthalmic instrument support which allows three distinctmovements including rotational movement from a stored position to anoperative position, longitudinal movement to present one or the other oftwo ophthalmic instruments in front of the patient and vertical movementto allow adjustment of the instruments relative to the height of thepatient and the doctor is found in U.S. Pat. No. 4,643,547.

Drawbacks of prior instrument delivery tables include difficulty inadjusting the various positions of the table, including the inability toinfinitely adjust within a predetermined range of movement as well asthe lack of an ability to adjust the position of the table toward andaway from the patient in a direction perpendicular to the longitudinalmovement between the two instrument positions. This would be helpful,for example, to accommodate for the various size ranges of patients thatwill be seated in the examining chair.

Various ophthalmic examination systems have also included lightingcontrol systems which adjust the room lights to a preset intensity whena particular instrument is activated. These systems have generally beendesigned so that the activation of a given instrument automatically setsthe room lighting conditions in accordance with a dimmer which is presetand prewired to the particular instrument. The main drawback of suchsystems has been the inability of the doctor to easily program each ofthe many instruments and electrical controls to activate a desired roomlighting condition in accordance with his or her particular needs ordesires. Also, these systems have generally been hard wired into theroom lighting wiring and are therefore more susceptible to various noiserelated problems in more complex systems. Such previous lighting controlsystems may be found in U.S. Pat. No. 3,724,931 and U.S. Pat. No.3,832,041 as well as in the model 905 "Pendulum Delivery System" sold byReliance Medical Products, Inc. of Mason, Ohio.

It would therefore be desirable to provide an ophthalmic instrumentdelivery system as well as a programmable lighting system which wouldmake examination of a patient by a doctor easier and which would providefor easier and fuller adjustment of both the instrument table and theroom lighting conditions according to any specific doctor'srequirements.

SUMMARY OF THE INVENTION

The present invention provides a uniquely position adjustable instrumentsupport table for use in conjunction with an examining chair and alighting system which allows the user to program the desired roomlighting independently for each of several instrument switches,examination lights or other electrical devices used during an ophthalmicexamination.

In accordance with a first aspect of the invention, the ophthalmicinstrument support table includes a base unit and a table top mounted tothe base unit by support structure allowing four degrees of freedom toadjust the location of the table top with respect to both the patientseated in the chair and the doctor examining the patient on the oppositeside of the table. Specifically, the table top is mounted to the baseunit by support structure including a movable support which allows thetable top to be moved from a stored position located in front of thebase unit to an operative position located adjacent to the examiningchair. The support structure further includes a first adjustable supportand locking mechanism for moving the table top along a first horizontalpath and locking the table top in a selected position along that firsthorizontal path. A second adjustable support and locking mechanism isprovided for moving the table top along a second horizontal path whichis transverse and preferably perpendicular to the first horizontal pathand which allows locking of the table top in a selected position alongthat second horizontal path. A third adjustable support and lockingmechanism is provided for moving and locking the table top selectivelywithin a vertical path. The second and third adjustable support andlocking mechanisms are infinitely adjustable along their respectivepaths of movement.

The movable support which allows the table top to be moved from thestored position to the operative position is preferably a pivotconnection and, more specifically, includes two rotating arms connectedbetween the table top and the base unit. This movable support actuatesat least one switch as it moves from the stored position to theoperative position and this switch may be used to cause power to bedirected to the instruments located on the table top.

The first adjustable support and locking mechanism allows the table topto be moved in a side-to-side fashion along the lengthwise dimension ofthe table top to position one or the other of the instruments on thetable top in front of the patient. Switches are provided at each of thetwo positions to activate or provide power to the particular instrumentlocated in front of the patient.

In a second aspect of this invention, a programmable lighting system isprovided which allows the doctor to easily program the room lightingconditions such that a programmed room lighting intensity is effectedupon activation of any of a plurality of input devices, such asinstruments, lights, switches or other electrical devices used by thedoctor during the examination. Thus, unlike past systems, the doctor mayeasily set the room lighting conditions according to his or herparticular desires and need not be forced to use factory preset lightingconditions.

Specifically, in a single zone option of the lighting control the doctormay quickly enter a programming mode and then activate a particularinput device to inform the control that that particular device is beingprogrammed to effect a certain lighting intensity of the room lights.The doctor uses a room lighting intensity control to adjust the roomlighting conditions for that given input device. When the input deviceis deactivated, the programmed lighting condition for that input deviceis saved into volatile or nonvolatile memory and each subsequentactivation of the input device automatically activates the programmedroom lighting intensity. A dual zone option is also provided and allowsprogramming of up to sixteen different "scenes" utilizing two differentbanks or circuits of room lights. For example, one bank of lights mightbe incandescent and one may be fluorescent. Each circuit of lights maybe adjusted in intensity and saved in the control as a "scene". Eachinput device may then correspond to and activate a differentprogrammable "scene".

An infrared transmitter is located on the ophthalmic instrument systemof the present invention and communicates with an infrared receiver in aconventional lighting control box which may be placed on the wall of theexamination room. The infrared transmitter conveniently clips to theinstrument pole of the system and may be adjusted vertically on the poleas well as rotationally to allow proper communication with the lightingcontrol box on the wall. The infrared transmitter is generally C-shapedsuch that it may be received in a sliding fashion on the pole. Thetransmitter includes a plurality of spaced LEDs which send the infraredsignals outwardly in a generally pie shaped pattern to also insure goodreception at the receiver. A fixation light box may optionally beattached to the wall opposite the patient and may receive infraredsignals from the transmitter as directed by the control and the inputfrom the doctor.

These and other advantages of the present invention will become morereadily apparent to those of skill in the art upon review of thefollowing detailed description of the preferred embodiments taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic perspective view of the instrument supporttable of the present invention with the table in operative position infront of an examining chair;

FIG. 2 is a diagrammatic top view of the examining chair and theinstrument support table being moved between the stored position and theoperative position;

FIG. 3 is a partially fragmented perspective view of the table basesupport structure and the pivoting arms which allow movement of thetable between the stored and operative positions;

FIG. 4 is a schematic top view of the pivoting arms and the lockingmechanism used for locking the table top in the operative position;

FIG. 5 is a schematic side elevational view of the pivoting arms andalso illustrating the locking mechanism shown in FIG. 4;

FIG. 6 is an enlarged detail showing the release mechanism which may beactuated to unlock the table top from the operative position;

FIG. 7 is a side elevational view of the table top and base unit showingthe table top in a raised position;

FIG. 8 is a side elevational view of the table top and base unit showingthe table top in a lowered position;

FIG. 9 is a bottom view of the table top and its base support structure;

FIG. 10 is a side elevational view of the table top and its base supportstructure;

FIG. 11 is a diagrammatic top view of an examination room showing therelative positions of the instrument support table, the patient, and thevarious lighting control components of the present invention;

FIG. 12 is an enlarged detail of the infrared transmitter of thelighting control system of the invention;

FIG. 13 is a schematic block diagram of a control system for operatingthe various electrical components, including the lighting controlcomponents of the invention;

FIG. 14 is a top view of the main control panel used for operating thevarious electrical components of the system, including the programmablelighting control system;

FIG. 15 is a flow chart showing the main routine executed by themicroprocessor of the control system shown in FIG. 14;

FIG. 16 is a flow chart showing the process steps of the read switchessubroutine in the main routine of FIG. 15;

FIG. 17 is a flow chart showing the process steps of the lap subroutinein the main routine of FIG. 15;

FIG. 18 is a flow chart showing the process steps of the lightingprogram subroutine in the main routine of FIG. 15;

FIG. 19 is a flowchart showing the process steps of an instrumentsubroutine representing an illustrative subroutine of variousinstruments and switches shown in the main routine of FIG. 15;

FIG. 19A is a flowchart illustrating a send IR subroutine of theinstrument subroutine illustrated in FIG. 19; and

FIG. 20 is a flowchart illustrating an interrupt subroutine of the mainroutine illustrated in FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIG. 1, an ophthalmic instrument and programmablelighting system 10 constructed in accordance with a preferred embodimentof the invention is shown. System 10 includes an adjustable table top 12which is connected to a base unit 14. System 10 may also include a desk16 which may be used for various purposes by the doctor. Table top 12 ismovable from a stored position directly over top of base unit 14 to theoperative position shown as directly in front of a patient seated withinan examining chair 18. Table top 12 may include, for example, twoophthalmic instruments 20, 22. These instruments may, for example, be aconventional slit lamp 20 and keratometer 22. System 10 further includesan overhead lamp 24 which is mounted to a pole 26. Also mounted to pole26 is an infrared transmitter 28 for use in sending infrared signals toa lighting control box and a fixation light box as will be describedfurther below in the discussion of the programmable lighting controlsystem. Three instrument wells 30 are provided for holding andrecharging three respective instruments 32 for use by the doctor. Thewells 30 each contain a conventional sensing circuit that senses whenthe instrument 32 has been placed into and withdrawn from its respectivewell 30 as will be discussed below. A hook or binding post 34 isprovided on base unit 14 for holding an indirect ophthalmoscope (notshown). A toggle switch 36 is provided next to hook 34 for controllingthe room lights as will be described below. Hook 34 is also part of aswitch which activates the indirect ophthalmoscope upon removal of theinstrument from hook 34.

A main control panel 38 is mounted to base unit 14 for controlling thefixation lights, the indirect ophthalmoscope, overhead lamp 24, the roomlights, chair 18, etc., as will be described further below. A smallercontrol panel 40 is disposed on table base 42 and, for example, includesswitches for controlling the room lights as well as the intensity of theslit lamp bulb switches (not shown) may also be provided to controlchair 18.

As will be described in detail, table top 12 is capable of being rotatedfrom a stored position directly over top base unit 14 to the operativeposition shown generally along a path indicated by arrow 44. Inaddition, table top 12 is capable of being infinitely adjusted along apredetermined range of movement toward and away from examining chair 18generally along the path indicated by arrow 46. Table top 12 is furthercapable of being shifted side-to-side as indicated by arrow 48 betweentwo positions. One position places instrument 20 in front of the patientseated in chair 18 having his or her chin resting on chin rest 52 andthe other of these positions places instrument 22 in front of thepatient with chin rest 52 remaining stationary as table top 12 is moved.Finally, table top 12 is also capable of being infinitely adjusted in avertical path indicated by arrow 50 and along a predetermined range ofmovement.

FIG. 2 schematically illustrates the movement of table top 12 between astored position in which table top 12 is disposed directly above baseunit 14 and along one side of chair 18. A pair of pivoting arms 54, 56carry table top 12 from the stored position to the operative position asshown with table top 12 finally disposed directly in front of chair 18.One arm 54 carries a locking plate 58 having a slot 60 which engages aspring loaded pin 62 carried by the other arm 56 to lock table top 12into the operative position.

Referring now to FIG. 3, the connections between table base 42 and arms54, 56 are shown. Arms 54, 56 include inner pivoting ends 54a, 56a whichare rigidly secured to the tops of respective vertical rods 64, 66. Rods64, 66 are contained for rotation within cylindrical tubes 68, 70. Outerends 54b, 56b of arms 54, 56 are secured to the underside of a plate 72which forms part of table base 42. Specifically, plates 74, 76 arerigidly attached to the underside of plate 72, as by welding, and plates74, 76 include respective pins 78, 80 secured thereto in a rigid mannersuch that pins 78, 80 extend vertically downward. Pins 78, 80 arereceived within cylindrical holes 82, 84 in ends 54b, 56b of arms 54,56. Thus, as table base 42 and table top 12 (FIG. 1) are rotated andarms 54, 56 pivot with rods 64, 66 rotating within tubes 68, 70,relative rotation takes place between pins 78, 80 and ends 54b, 56b.

Referring now to FIG. 3 taken in conjunction with FIGS. 4-6, arms 54, 56are locked together by a locking plate 58 when table 12 reaches theoperative position (FIG. 1). As shown best in FIG. 5, locking plate 58rides up over spring loaded pin 62 and compresses spring 86 until pin 62registers within slot 60 of plate 58. The pin 62 and compression spring86 are more specifically in an eccentric 87 which is mounted within end56a of arm 56. The eccentric allows the pin to be adjusted to accountfor misalignment with locking plate 58, so that the arms 54 and 56 areat the extreme end of their in use travel to allows for more stablesecurement in the operative position. When the alignment of theeccentric is achieved, a set screw 89 is tightened to secure eccentric87 in position. As shown in FIG. 6, a release mechanism 88 is providedwithin table top 12 (FIGS. 1 and 10) and is used to depress springloaded pin 62 to release its locking engagement with plate 58.Specifically, release mechanism 88 includes a pivot connection 90 aboutwhich release mechanism 88 rotates when a cable 92 is pulled. Thiscauses end 94 of release mechanism 88 to depress spring loaded pin 62into its receiving bore 96 thereby releasing its engagement within slot60 of plate 58. This allows movement of table top 12 back into thestored position generally along the path illustrated in FIG. 2. Theactuation and specific location of attachment of the release mechanism88 will be described further below with reference to FIG. 10.

The vertical adjustment of table top 12 will now be described withrespect to FIGS. 7 and 8. FIG. 7 shows table top 12 in a fully raisedposition while FIG. 8 shows table top 12 in a fully lowered position.Infinitely adjustable movement is allowed between these two positions.The mechanism for allowing this vertical adjustment is contained withinbase unit 14. Much of the supporting structure of base unit 14 has beendeleted for clarity in FIGS. 7 and 8 but generally comprises framemembers, such as frame members 98, 100, 102 as well as upper and lowerpanels with only lower panel 104 being shown in the drawings. Casters106 may also be provided for easier movement of base unit 14.

It will be appreciated from a review of FIGS. 7 and 8 that the tubes 68,70 which receive rods 64, 66 for rotation are raised and lowered withrespect to base unit 14. To this end, tubes 68, 70 are rigidly securedtogether at their respective upper ends by a connecting plate 108 andare rigidly secured together at their lower ends by horizontal plates110, 112 as well as vertical plates, with only one vertical plate 114being shown. Vertical plates 114 are secured to upper and lower bushings116, 118 which receive vertical rods 120, only one of two rods 120 beingshown in the drawings. A counterweight system 122 is provided to assistthe operator in raising table top 12 and the various componentsconnected thereto. Counterweight system 122 comprises two counterweights124, 126 attached to cables 128, 130 and received for vertical movementalong respective vertical rods 132, 134. Cables 128, 130 extend upwardlyover respective pulleys 136, 138 and over a double pulley 140. The endsof cables 128, 130 opposite to counterweights 124, 126 are attached to acable mount 142 which is rigidly secured to plate 110.

Another vertical rod 144 is provided within base unit 14 and receives aconventional locking mechanism 146. Locking mechanism 146 comprises apair of plates 148, 150 which receive rod 144 through aligned bores ineach plate 148, 150. The ends of each plate 148, 150 are connected to acable 152 while the opposite ends are received between a pair of pins154. Another pin 156 is disposed on the opposite side of vertical rod144 and between plates 148, 150. A spring 153 is received about verticalrod 144 and between plates 148, 150 to provide a normal spring bias ofplates 148, 150 into a unparallel orientation thus effectively jammingplates 148, 150 against vertical rod 144 and preventing any verticalmovement of table top 12. When cable 152 is pulled via a push buttonassociated with table top 12 to be described below, plates 148, 150 aremoved into a parallel orientation against pins 154, 156 with respect toeach other as shown in FIGS. 7 and 8 thus vertically aligning the holesin plates 148, 150 and allowing vertical movement of locking mechanism146 along vertical rod 144.

As further shown in FIGS. 3, 7 and 8, a pair of cams 66a, 66b aresecured to the bottom of rotatable rod 66. One of these cams 66a acts asa detent mechanism to positively restrain table top 12 in the storedposition with a ball and spring assembly 158 while the other of thesecams 66b actuates a switch 162 by way of a small lever switch 162instructs the control, to be described below, to provide power to theinstruments located on table top 12 (FIG. 1).

The support structure which allows both the side-to-side shifting oftable top 12 in front of chair 18 as well as the adjustment of table top12 both toward and away from examination chair 18 (FIG. 2) will now bedescribed with reference to FIG. 9. Table base 42 generally comprises asupporting frame 170 which includes front and rear support rails 172,174. A pair of guide rods 176, 178 are rigidly fastened between frontand rear support rails 172, 174 by respective bolts 180. Guide rods 176,178 each carry two sliding bearings 182. One bearing 182 on each guiderail 176, 178 is rigidly secured to one of a pair of support arms 184,186 which extend lengthwise beneath table top 12. Support arm 184 isfurther connected to a pair of short bearing support members 188, 190and support arm 186 is rigidly secured to a pair of long bearing supportmembers 192, 194. A cross member 196 is also bolted between the pair oflong bearing support members 192, 194. A chin rest support plate 198 isbolted to the underside of arms 184, 186 and cross member 196. One end198a serves a mounting location for chin rest 52 (FIG. 1). Bearings (notshown) contained respectively within short bearing support members 188,190 and long bearing support members 192, 194 receive guide rods 200,202 in a sliding manner. Guide rods 200, 202 are suitably secured to themovable table top 12 in a rigid manner. Thus, in a manner to bedescribed more completely below, it will be appreciated that table top12 and its attached guide rods 200, 202 may shift from right to left asviewed in FIG. 9 with respect to bearing support members 188, 190, 192,194, arms 184, 186 and table base 42.

Front and rear adjustability of table top 12 is provided by the slidingmovement of arms 184, 186 along guide rods 176, 178 and within thelimits established by bumpers 204, 206. This will simultaneously adjustthe position of table top 12, rods 200, 202, members 188, 190, 192, 194,196, 198 and chin rest 52 (FIG. 1) with respect to the remainingstructure of base 42. Bumper 204 will be contacted by arm 184 at one endof the range of movement while bumper 206 will contact rear support rail174 at the other end of the range of movement. A locking mechanism 208identical to locking mechanism 146 described with respect to FIG. 8 isprovided for locking table top 12 into a desired position within thisrange of movement. Locking mechanism 208 is operated by a push button210 extending through an outer surface of table base 42. Specifically,push button 210 pulls a cable 212 which pivots two plates 214, 216 intoa parallel relationship with respect to each other thereby allowingsliding movement along rod 218 as previously described. As alsopreviously described, when push button 210 and cable 212 are released,plates 214, 21 6 return to their normally biased unparallel orientationby a spring 217 thereby jamming against rod 218 and preventing movementof bearings 182 along guide rods 176, 178.

A second push button 220 is provided on table base 42 for operating thepreviously described release mechanism 88 (see FIG. 6). Specifically,when push button 220 is depressed, cable 92 pulls against and pivotsrelease mechanism 88 about pivot connection 90 with table base 42 andmoves end 94 into engagement with pin 62 (FIG. 6). This releases tabletop 12 from the operative position and allows the doctor to move it backinto the storage position (FIG. 2).

A pivotal lever 222 is also provided beneath table base 42 and pullscable 152 when squeezed upwardly by the user. As previously describedwith respect to FIGS. 7 and 8, cable 152 operates the locking mechanismassociated with the vertical adjustment of table top 12. Therefore,cable 152 is shown extending away from table 12 with the understandingthat it is appropriately directed into base unit 14 as shown in FIGS. 7and 8.

Also leading into table base 42 from, for example, base unit 14 is acable assembly 224 connected with the control system to be described andleading to control panel 40 on table base 42 (FIG. 10). In addition,both high and low voltage cable assemblies 228, 230 extend into tablebase 42 for respectively powering instruments 20, 22 (FIG. 1) in theinstance where one of these instruments requires high voltage power andone requires low voltage power. High and low voltage cable assemblies228, 230 include coil portions 228a, 230a which are received about aguide rod 232 and which respectively extend and contract with the leftand right shifting movement of table top 12 as viewed in FIG. 9.

The shifting of table top 12 right to left as viewed in FIG. 9 iscontrolled by a release mechanism 240 which generally comprises a handle242 attached by a pivot connection 244 with chin rest support plate 198.A pin 246 is also connected to handle 242 by a pivot connection 248 atone end and bears against a compression spring 250 at the opposite end.Pin 246 carries a roller 252 extending outwardly therefrom and outwardlyof a slot 254 within plate 198. Roller 252 registers within a detent 256in guide rod 200 to lock table top 12 into the position shown in FIG. 1with instrument 20 aligned with a patient sitting in chair 18. Anotherdetent 258 is located in guide rod 200 and defines the second positionof table top 12 in which instrument 22 is aligned with chair 18. Torelease table top 12 from one position, handle 242 is depressed to movepin 246 inwardly against spring 250 and move roller 252 out of detent256. This allows table top 12 to be shifted to the left as viewed inFIG. 9 with roller 252 rolling against guide rod 200 until detent 258 isreached. When detent 258 is reached, roller 252 will snap into place bythe force of spring 250. Bumpers may be provided as well to stop themovement of table top 12 at each of these two positions. Only one ofthese bumpers 260 has been shown in FIG. 9.

In the first position shown in FIG. 9, a switch 262 is activated by afastener head 264 located on the underside of table top 12. When switch262 is activated in this manner, power is supplied by the low voltagecable assembly 228 to instrument 20 and power is not supplied instrument22 (FIG. 1). When table top 12 is shifted to the second position suchthat roller 252 registers within detent 258, a second switch 266 isactivated by a second fastener 268 located on the underside of table top12. This deactivates switch 262 thereby cutting off power to instrument20 and activates switch 266 thereby supplying power from the other ofthe high and low voltage cable assemblies 228, 230 to instrument 22(FIG. 1). In the preferred embodiment shown, this position will supplypower from cable assembly 230. Switches are mounted to a plate 270 andmay, for example, be obtained from Cherry Electrical Products located inWaukegan, Ill. and sold under part number E31-00K.

Finally, table top 12 is also provided with a mechanism for preventinginadvertent raising of chair 18 into table top 12. In this regard, andreferring now to both FIGS. 9 and 10, a pair of switches 280, 282 arerespectively mounted to arm 184 and cross member 196 and are designed tobe activated by a plate 284 connected to the underside of table top 12by spring loaded fastener assemblies 286. As will be appreciated by areview of FIG. 10, if chair 18 (FIG. 1) is raised to such an extent thatthe patient's lap contacts and pushes against plate 284, one or both ofswitches 280, 282 will be activated and will send a signal to thecontrol system, to be described below, which will then either stop allmovement of the chair or reverse the movement of chair 18. Switches 280,282 may also be obtained from Cherry Electrical Products under partnumber E31-50K.

Referring now to FIG. 11, a schematic layout of an examination room 298is shown incorporating the instrument delivery system and programmablelighting system 10 of the present invention. As will be described below,base unit 14 preferably contains the various electrical hardware andcontrol components of the programmable lighting system except for theinfrared transmitter 28 which is mounted to instrument pole 26 and whichcommunicates with receivers contained within a room lighting control box302 and a fixation light control box 304 mounted on one wall of room298. Fixation light box 304 includes three fixation lights 306, 308, 310which some doctors use for certain examination procedures in which thepatient seated in chair 18 is told to focus on one of the lights 306,308, 310. Fixation lights 306, 308, 310 may optionally be those standalone units with separate receivers that the doctor could place anywherein room 298.

As shown in more detail in FIG. 12, the unique infrared transmitter 28of the present invention includes a generally C-shaped body 314 whichsimply clips onto pole 26 (FIGS. 1 and 11). Body 314 is sized to allowsliding movement along pole 26. Three angularly spaced LEDs 318, 320,322 are incorporated into the C-shaped body 314 for transmitting theinfrared signals to respective receivers contained in boxes 302, 304. Afourth LED, which may be red in color, may also be included to indicateactivation of transmitter 300. A suitable, conventional wire and plugassembly 324 extends from body 314 and is connected to a centralprocessing unit of the control to be described.

With reference now to FIG. 13, a block diagram of a control system 330constructed in accordance with the present invention is shown. Controlsystem 330 includes a control circuit 332 based around an 8 bitmicroprocessor 334 (Microchip Technology, Chandler, Ariz. under partnumber P1C16C64) which controls overall operation of the control system330. Preferably, microprocessor 334 and related control logic aremounted on a conventional printed circuit board and comprise controlcircuit 332. This conventional hardware, including the other necessary,conventional and electrical control components such as a power entrymodule, fuses, and a transformer may be mounted in base unit 14. As willbe described in more detail below with reference to FIG. 15,microprocessor 334 is responsive through conventional programmingtechniques to various switch inputs. Representative switch inputsinclude those received from fixation light membrane switches 338, mainpanel membrane switches 340 and instrument table membrane switches 40(also see FIG. 10). Main panel switch plates 338, 340 form main controlpanel 38 as shown in FIG. 1 and are described further below with respectto FIG. 14.

Further switch inputs include a room light switch 344 which enablesophthalmoscope hanger switch 346 associated with hook 34 in FIG. 1 tocontrol the room lights in an operator programmable manner. When switch344 is in one position, activation of switch 346 will cause a programmedroom lighting condition to occur and when switch 344 is in the otherposition, room lighting conditions will not change. A lap switch 348(representing switches 282, 284 in FIGS. 9 and 10), a table operativeposition switch 350 (representing switch 162 in FIGS. 7 and 8),instrument well sensor circuits 352 associated with each of theinstrument wells 30 (FIG. 1), and dip switches 354 are representative ofbut not necessarily all inclusive of additional input devices intomicroprocessor 334. As shown in FIG. 13, all switch inputs except fordip switches 354 are operatively connected to microprocessor 334 throughoptical buffers 336 (Sharp PC847). The optical buffers 336 provide aninterface circuit which electrically isolates the various switch inputsconnected thereto from the microprocessor terminals connected to inputand output lines 337. In this way, only a low voltage signal from apower supply 339 in a preferred range of +5 V-+12 V is used to operatethe system from the various switch inputs.

Dip switches 354 may be used to configure control circuit 332 to thepreferences of the user and, for example, the various power requirementsof different electrical components. With respect to the presentinvention, dip switches may be used to enable and disable room lightingprogrammability associated with the various switches, instruments, etc.Dip switches 354 may also be used to indicate to the control that switch346 has been installed and this will override switch 376 on controlpanel 38 (FIG. 14). Dip switches 354 may further be used to controlvoltage sent to certain instruments in cases, for example, in which atype of instrument may use a bulb requiring 6 volts or 7 volts.

Referring now briefly to FIG. 14, switch plate 340 of main control panel38 includes three switches for operating the examination chair 18(FIG. 1) in a conventional manner. These switches include a chairraising switch 356, a chair lowering switch 358 and an "auto" switch 360which lowers chair 18 to a lower limit of the chair travel to allow thepatient to exit. Switch plate 340 further includes an "AUX1" switch 362which turns either 115 V or 230 V on and off to an "AUX1" outlet 412 inFIG. 13 associated with the system 10. In practice, the primary purposeof this switch is to turn a projector on and off, however, it might beused for any instrument which runs on 115 V or 230 V power. A standbyswitch 364 is also provided on main switch plate 340. The standby switchturns secondary power on and off to system 10. Specifically, this switchmay be designed to cause 115 V or 230 V to be applied to an "AUX2"outlet as well as a keratometer outlet.

Main switch plate 340 further includes on/off switches 366, 270, 274 forrespectively turning the room lights, overhead lamp 24 (FIG. 1), and anindirect ophthalmoscope (not shown) associated with binding post 34(FIG. 1) on and off. In addition, each of these switches 366, 370, 374include corresponding intensity adjustment switches 368, 372, 376 forrespectively varying the intensity of the room lighting, overhead lamp24, and the indirect ophthalmoscope bulb. Secondary switch plate 338 ofmain control panel 38 includes three on/off switches 378, 380, 382 forrespectively operating the three fixation lights 306, 308, 310 shown inFIG. 11.

Microprocessor 334 decodes and validates the various switch inputs justdescribed as those of skill in the art will contemplate and is furtheroperatively connected with the necessary timers 384, registers 386 and atone generator 388. Output signals on lines 390, 392, 394, 396 and 398are provided on output ports of microprocessor 334 and respectivelyconnect to an overhead lamp dimmer 400, a table instrument dimmer 402,an indirect ophthalmoscope dimmer 404, a mechanical relay 406 andinfrared transmitter 28. Dimmers 400, 402, 406 may be conventional andobtained from Sharp Corporation under part number S 102S01. Likewise,mechanical relay may be obtained from Potter Brumfield under part numberRKA. Dimmers 400, 402, 404 are connected to a low voltage AC powersupply which preferably supplies power in the range of 0-12 V.Mechanical relay 406 is connected to a high voltage power supply asshown and previously mentioned which may supply either 115 V or 230 Vpower. An appropriate power supply, such as a DC power supply, may beprovided in control circuit 332 and connected to a slit lamp fixationlight 408 which is operated by a switch 410 (FIG. 3) when table 12 ismoved into the operative position.

As further shown in FIG. 13, dimmers 400, 402, 404 are respectivelyconnected to the overhead lamp 24, table 12 and indirect ophthalmoscope410. Indirect ophthalmoscope, as mentioned above, may be operatedthrough a switch activated by binding post or hook 34 (FIG. 1). Switches262, 266 discussed above with reference to FIG. 9 are represented inFIG. 13 as respectively controlling the first and second instruments 20,22 (FIG. 1). Table instrument dimmer 402 thus provides the same lightingintensity adjustment for each of the light bulbs associated withinstruments 20 and 22. High voltage "V_(AC) " is connected to the secondinstrument 22. Mechanical relay 406 provides high voltage power to anauxiliary outlet 412 in a switched manner as previously mentioned. Highvoltage power to another unswitched auxiliary outlet 414 is alsosupplied when the system is powered on. AC power is also supplied tooverhead lamp 24, table 12, as previously described, and indirectophthalmoscope 410 as shown in FIG. 13.

The programmable room lighting system of the present invention is basedaround a conventional room lighting control 302 which may be obtainedfrom Lutron of Coopersburg, Pa. under part number GRX-3002. Roomlighting control 302 has the capability to control either a single zoneor a dual zone or circuit of lights (two circuits) of lights dependingon the needs or desires of the users.

The present invention is capable of utilizing either of these twooptions as shown in FIG. 13. In accordance with the invention, roomlighting conditions are programmable such that the doctor may easilyprogram the desired room lighting condition to occur upon activation ofeach of several instruments or switches. For example, upon activation ofany of switches 344, 346, 350, 352, 362, 364, 378, 380 and 382, theseparately programmed room lighting conditions or intensity willautomatically change to the programmed state for that particular switch.This programming is discussed further below but essentially, themicroprocessor 334 sends a data coded signal to either the infraredreceiver 416 associated with the single zone option or the infraredreceiver 418 associated with the two zone option of lighting control 302to instruct the lighting control, which includes the necessary roomlight dimmers, to adjust the intensity of the single circuit 420 of roomlights in the single zone system or the two circuits 422, 424 of roomlights associated with the two zone option to the preprogrammed statecorresponding to that data coded signal. In the single zone option, theinfrared signal simply transmits a data code between zero and 100 with100 being the most intense lighting condition and zero representing theroom lights being off. Such a code is programmed into memory for each ofthe above mentioned programmable switches in a very easy manner by thedoctor as will be described below.

The two zone option of the lighting control 302 includes 16 separate"scenes". With each scene, each circuit of lights is separately adjustedto a desired intensity and the scene is saved into memory in thelighting control 302. With this two zone option, therefore, each scenemay represent a desired lighting condition for a given switch orinstrument and activation of that switch or instrument will causemicroprocessor 334 to send a signal 398 through infrared transmitter 28which is coded and recognized by lighting control 302 as representing aparticular scene out of the sixteen possible scenes. The scenes areprogrammed at the lighting control 302 in the two zone option in a knownmanner associated with that commercially available control box. Themicroprocessor 334 sends the specific data coded signal associated witha particular scene upon activation of a switch or instrument. Forexample, "scene 1" may correspond to I/O hanger switch 346, "scene 2"may correspond to table operative position switch 350, etc. The doctormay simply be given a list of sixteen possible switches and/orinstruments which correspond to the sixteen different scenes in the twozone option and may independently program the scenes corresponding toeach instrument or switch.

Microprocessor 334, when instructed by fixation light membrane switches378, 380, 382 (FIG. 14), sends another appropriate data code throughinfrared transmitter 28 to infrared receiver 426 of fixation light box304 (FIG. 11) to cause a particular fixation light 306, 308, 310 toactivate. Upon activation of any of switches 378, 380, 382microprocessor 334 may also send a programmed data code through infraredtransmitter 28 to lighting control 302 to adjust the lighting conditionsaccording to the programmed conditions set by the doctor with respect toone or all of the fixation light switches 378, 380, 382. The system maybe easily configured such that if a particular switch or instrument hasnot been enabled to be programmed by the doctor to cause lightingcontrol 302 to adjust the room lights 420 (signal zone) or 422, 424(dual zone), the room lighting conditions will remain unaffected byactivation of the switch or instruments to a fallback condition such as"full on". Also, a default setting is preferably provided at the factoryto account for the situation in which a switch which is enabled to beprogrammed is not actually programmed by the doctor.

FIG. 15 is a flowchart illustrating a main routine 450 including processsteps executed by microprocessor 334 of control circuit 332.Microprocessor 334 executes the main routine upon application of powerto the control circuit 332. The main routine 450 is iterately executedat a suitable rate for the particular application. For example, a mainroutine cycle loop time suitable for debouncing switches as used in thesystem 330 is 50 milliseconds. The main routine 450 continuouslyiterates until the power to control circuit 332 is turned off. Atprocess step 452, main routine 450 initializes the hardware elements ofthe system such as the timers 384, registers 386, tone generator 388,etc.

FIG. 20 illustrates a flowchart of a subroutine 454 which is the nextstep in main routine 450 and is used for initializing various interruptsassociated with control circuit 332. Specifically, at process step 530,a "zero cross" check is performed approximately every 8 milliseconds andchecks to establish whether an AC voltage associated with microprocessor334 has "crossed through zero", i.e., whether the sine wave of the 50 or60 Hz line frequency has crossed through the zero point. This is aconventional, reliable method of timing in control circuits such ascontrol circuit 332. If the zero point has been crossed, the process atstep 532 detects whether overhead lamp 24 (FIG. 1) is on. If the lamp ison, the process at step 534 initializes a dimmer interrupt associatedwith dimmer 400 (FIG. 13). The initialization of this dimmer interruptessentially sets up a timing mechanism to wait a predetermined amount oftime, such as 4 milliseconds, to turn dimmer 400 on when control circuit332 is so instructed. If lamp 24 is not on, the process at step 536turns the lamp 24 as well as the interrupt off. Next, at process step538 the process detects whether the indirect ophthalmoscope or the slitlamp are activated. If either the indirect ophthalmoscope or the slitlamp are on, the process at step 540 initializes another dimmerinterrupt associated with dimmer 404 (FIG. 13). If the indirectophthalmoscope and the slit lamp are detected to be off at process step538, the process at step 542 turns the indirect ophthalmoscope and slitlamp off as well as the interrupt off. Next, at process step 544 thecontrol detects whether a beeper timer is on and, if so, updates thetimer at process step 546. If the beeper timer is not detected as beingactive or on, the beeper is turned off at process step 548. Processsteps 536, 542 and 548 are essentially failsafe measures which ensurethat the respective components are, in fact, off. If no zero cross isdetected at step 53, the process at step 550 determines whether the lampinterrupt has timed out. If the lamp interrupt has timed out, theprocess at step 552 triggers the lamp dimmer 400 (FIG. 13). If the lampinterrupt is not detected to be timed out, the process at step 554detects whether the indirect ophthalmoscope or the slit lamp interrupthas timed out. If this interrupt has timed out, the process nextdetermines at step 556 whether the slit lamp is on. If the slit lamp ison, the process at step 558 triggers the slit lamp dimmer. If the slitlamp is not on, the process at step 560 triggers the indirectophthalmoscope dimmer. The process then returns to the main routine 450.

Next, at process step 456, main routine 450 establishes a set of defaultparameters for status bits, output registers, etc.

At process step 458, main routine 450 executes a read switchessubroutine 600 as illustrated in FIG. 16. The first step 602 of the readswitches subroutine 600 reads the states of the various input switcheson the outputs 337 from optical buffers 336 (FIG. 13). The states of thevarious input switches are individually decoded and validated at processstep 604 such that only predetermined acceptable input switch states arerecognized. For example, the programming mode to be described below isactivated by simultaneously actuating a combination of two switches,such as the raise and lower arrow switches 368 (FIG. 14).

At process step 606, the decoded and validated switch states are loadedinto a command state output register within the group of registers 386.Appropriate status states are set in status registers included withinthe group of internal registers 386 as well. The status registers areused to track the current state of the control system operation asdetermined by, for example, the doctor. For example, status bits andregisters may be used to indicate to the control whether the set up orprogramming mode has been activated, etc., as those of skill in the artwill readily recognize.

Returning to FIG. 15, the main routine 450 then proceeds at step 460 toexecute a "lap" subroutine 462 as illustrated in FIG. 17 to determinewhether either one of the lap safety switches 282, 284 (FIGS. 9 and 10)have been actuated. Specifically, at process step 464 microprocessor 334detects whether either one of these lap safety switches has beenactivated. If either one has been activated, all outputs to chair 18(FIG. 1) are turned off at process step 466. Alternatively, themicroprocessor 334 may direct the chair control to reverse the outputsto the chair 18 such that the chair is lowered away from table top 12(FIG. 1). If neither of the lap safety switches is detected to beactivated, the process returns to the main routine 450.

Main routine 450 then proceeds at process step 468 to execute aprogramming mode subroutine as illustrated in FIG. 18. This programmingmode is used only for the single zone option discussed above. First, atstep 472, the lighting program subroutine 470 detects whether thecurrent state of the switches which have been decoded and validated isrepresentative of actuation of a set up switch. As previously mentioned,the "set up switch" may actually involve simultaneously actuating acombination of switches, such as switches 368 (FIG. 14). If activationof the set up switch is detected, the process at step 474 determineswhether the set up mode is currently active. If the set up mode iscurrently inactive, the process at step 476 sets the set up mode flag.Otherwise, the process clears the set up mode flag at process step 478.Consequently, in steps 474, 476 and 478, the process successivelyactivates and deactivates the set up mode in response to successiveactuations of the set up switch. After setting the set up mode flag, theprocess at step 480 activates the tone generator 388 (FIG. 13) toproduce two short beeps and/or causes suitable LEDs to activateindicating to the doctor that the programming or "set up" mode has beenactivated. If the set up mode flag is cleared, the process at step 482activates the tone generator 388 to produce two long beeps and/or causessuitable LEDs to activate indicating that the programming or "set up"mode has been exited. Thereafter, the process returns to main routine450.

If, at process step 472, the set up switch state is not detected, butthe process at step 484 detects that the set up is activated, theprocess determines whether any of the programmable input switches tomicroprocessor 334 has been actuated. Representative switches areillustrated by process steps 486-498 in FIG. 18. These include any ofthe fixation light switches 378, 380, 382 (FIG. 14), room light switch366 (FIG. 14), indirect ophthalmoscope hanger switch operated by hook 34(FIG. 1), table operative position switch 162 (FIGS. 7 and 8), sensingcircuits associated with instrument wells 30 (FIG. 1), "AUX1" switch 362(FIG. 14) and standby switch 364 (FIG. 14). If any of these switches aredetected as activated, the process at step 500 next determines whetherthe room lighting intensity is being adjusted upwardly by the doctor byactuation of switch 368 on main switch plate 340 (FIG. 14) and, if so,the process at step 502 adjusts the room lights through lighting control302 to be more intense and Stores this value in either volatile ornonvolatile memory for the particular switch or instrument which hasbeen activated. If instead the room light intensity is being adjusteddownwardly by operation of switch 368, the process detects this atprocess step 504 and accordingly adjusts the intensity of the roomlights downward through control 302 and stores this for the particularswitch or instrument. The process then returns to the main routine 450.

Returning to FIG. 15, main routine 450 then proceeds through steps todetermine active or inactive states for various switches, lights andinstruments associated with the system. Each of process steps 508, 510,512, 514, 516, 518, 520 is represented by the "instrument" subroutine522 illustrated in FIG. 19. Specifically, at process step 564, thecontrol detects whether one of the switches has changed its state fromactive to inactive or vice versa. If a change in switch state has beendetected at step 564, the process at step 566 detects whether theinstrument (or switch, light, etc.) is on. If no change in switch stateis detected at step 564, the process returns to main routine 450. If theprocess detects that the instrument, switch, etc., is off at step 566,the process turns it on at step 568. If it is detected to be on at step566, the process turns the instrument, switch, etc., off at step 570.After either step 568 or 570, the process at step 572 determines whetherthe room light control has been enabled, such as by a dip switch 354(FIG. 13). If the room light control has not been enabled, the processreturns to main routine 450. If room light control has been enabled, theprocess at step 574 determines whether the system includes the two zoneoption, if so, the process at step 576 picks a "scene" corresponding tothat particular instrument, switch, etc. If the two zone option is notdetected, the process at step 578 picks the programmed intensity forthat particular instrument, switch, etc. If the instrument, switch,etc., is turned off at step 570, then the process in step 576 or 578 maypick a default intensity or scene such as "full on" or the process mayrevert back to the intensity or scene which was active before theinstrument, switch, etc., was turned on. After the process performseither step 576 or 578, the control sends the appropriate infrared datacode at process step 580 and then returns to main routine 450. Processstep 580 involves a separate subroutine as discussed below.

The subroutine involved with sending the infrared code is illustrated inthe flowchart of FIG. 19A. Specifically, at process step 582 ofsubroutine 580, the process creates infrared data for communicating withthe lighting control 302 of control system 330. As is known to those ofskill in the art, infrared codes may be created in a hex numberingsystem, for example, comprising 36 bits of information. Different 36 bitcodes are sent representing different room lighting outputs in eitherthe single zone or dual zone option. The system retrieves the infrareddata in bytes and transmits this data in bits to the room lightingcontrol 302. Therefore, at process step 584, the control determineswhether the last bit of a given byte of the data string or code has beensent to lighting control 302. If it has not, the process at step 586sends or transmits the next byte to the lighting control 302. If itdetects that the last bit of a given has been sent to lighting control302, the process at step 588 detects whether the last byte of the datastring has been transmitted to the lighting control 302. If it has, theprocess returns to main routine 450. If it has not, the processretrieves the next byte at 590 and iterates through steps 584 and 586until the entire 36 bit data string has been transmitted to lightingcontrol 302 whereupon the subroutine will be exited and the process willreturn to main routine 450.

While a preferred embodiment of the present invention has been detailedherein, those of ordinary skill will recognize many modifications,substitutions of components and departures from this detaileddescription which nevertheless fall within the spirit and scope of theinvention as set forth in the appended claims.

What is claimed is:
 1. An ophthalmic instrument support table for use inconjunction with an examining chair, said instrument support tablecomprising:a base unit; a table top mounted to said base unit by supportstructure including a movable support operative to move said table topfrom a first, stored position adjacent said base unit to a second,operative position adjacent said chair, said support structure furtherincludingi) a first adjustable support and locking mechanism for movingsaid table top along a first horizontal path and locking said table topin a selected position along said first horizontal path; ii) a secondadjustable support and locking mechanism for moving said table top alonga second horizontal path transverse to said first horizontal path andlocking said table top in a selected position along said secondhorizontal path; and, iii) a third adjustable support and lockingmechanism for moving and locking said table top in a vertical path andlocking said table top in a selected position along said vertical path.2. The instrument support table of claim 1 wherein the movable supportincludes at least one pivot connection disposed between said table topand said base unit for allowing said table top to be rotated betweensaid stored position and said operative position.
 3. The instrumentsupport table of claim 2 wherein said pivot connection includes tworotating arms operatively connected between said table top and said baseunit.
 4. The instrument support table of claim 3 wherein said arms areconnected to respective rods contained for rotation within tubularmembers, said tubular members being mounted for vertical movement withinsaid base unit.
 5. The instrument support table of claim 4 furtherincluding a counterbalancing mechanism connected to said tubular membersfor counterbalancing vertical movement of said table top and componentsassociated therewith.
 6. The instrument support table of claim 3 furtherincluding a switch mounted to be activated as said table top is movedfrom said stored position to said operative position.
 7. The instrumentsupport table of claim 1 wherein said second and third support andlocking mechanisms allow infinite adjustment and locking withinrespective, predetermined ranges of movement.
 8. The instrument supporttable of claim 1 wherein said second horizontal path is perpendicular tosaid first horizontal path.
 9. The instrument support table of claim 1further including a selectively actuable locking mechanism operativelyconnected to said movable support for locking said table top in theoperative position.
 10. The instrument support table of claim 9 whereinsaid movable support includes two rotating arms operatively connectedbetween said table top and said base unit and said selectively actuablelocking mechanism includes locking elements on each arm which engage andlock said arms together when said table top is moved to said operativeposition.
 11. The instrument support table of claim 9 wherein said tabletop is mounted on a table base which includes a control panel and saidcontrol panel includes a first actuator for actuating the selectivelyactuable locking mechanism.
 12. The instrument support table of claim 11wherein said control panel further includes a second actuator foractuating a second locking mechanism forming part of said secondadjustable support and locking mechanism.
 13. An ophthalmic instrumentsupport table for use in conjunction with an examining chair, saidinstrument support table comprising:a base unit; a table base mounted tosaid base unit by a movable support operative to move said table basefrom a first, stored position adjacent said base unit to a second,operative position adjacent said chair; a table top having a lengthdimension and a shorter width dimension, said table top mounted to saidtable base for movement with said table base between said storedposition and said operative position such that said length dimensionextends across a front portion of said chair in said operative position;and, an adjustable table support and locking mechanism for moving saidtable top with respect to said table base along a horizontal path andlocking said table top in a selected position along said horizontalpath, Wherein said horizontal path is disposed perpendicularly to saidlength dimension.
 14. The ophthalmic instrument support table of claim13 further comprising a second adjustable support and locking mechanismfor moving said table top along a second horizontal path parallel tosaid length dimension and locking said table top in a selected positionalong said second horizontal path.
 15. The ophthalmic instrument supporttable of claim 14 further comprising a third adjustable support andlocking mechanism for moving and locking said table top and said tablebase in a vertical path and locking said table top and said table basein a selected position along said vertical path.
 16. The instrumentsupport table of claim 13 wherein the movable support includes at leastone pivot connection disposed between said table base and said base unitfor allowing said table top and said table base to be rotated betweensaid stored position and said operative position.
 17. The instrumentsupport table of claim 16 wherein said pivot connection includes tworotating arms connected between said table base and said base unit. 18.The instrument support table of claim 17 wherein said arms are connectedto respective rods contained for rotation within tubular members, saidtubular members being mounted for vertical movement within said baseunit.
 19. The instrument support table of claim 18 further including acounterbalancing mechanism connected to said tubular members forcounterbalancing vertical movement of said table top and componentsassociated therewith.
 20. The instrument support table of claim 17further including a switch mounted to be activated as said table top ismoved from said stored position to said operative position.
 21. Theinstrument support table of claim 13 further including a selectivelyactuable locking mechanism operatively connected to said movable supportfor locking said table top and said table base in the operativeposition.
 22. The instrument support table of claim 21 wherein saidmovable support includes two rotating arms connected between said tablebase and said base unit, said selectively actuable locking mechanismincluding locking elements on each arm which engage and lock said armstogether when said table base and said table top are moved to saidoperative position.
 23. The instrument support table of claim 21 whereinsaid table base includes a control panel and said control panel includesa first actuator for actuating the selectively actuable lockingmechanism.
 24. The instrument support table of claim 23 furthercomprising a second adjustable support and locking mechanism for movingsaid table top along a second horizontal path parallel to said lengthdimension and locking said table top in a selected position along saidsecond horizontal path, and wherein said control panel further includesa second actuator for actuating a second locking mechanism forming partof said second adjustable support and locking mechanism.